The Clinical Core is the key resource ofthe ADRC. Principal goals are to: (1) enroll, evaluate, characterize, and follow elderly persons, non-demented, with mild cognitive impairment, or with Alzheimer's disease or other forms of dementia, from diverse ethnic backgrounds; (2) obtain and maintain high quality data on these subjects for the Center and for the National Alzheimer's Coordinating Center (NACC); (3) provide wellcharacterized patients for clinical trials and other allied research projects; and (4) operate an autopsy program to maximize utility and amount of material for the Neuropathology Core. Goals are to increase understanding ofthe etiologies of mild cognitive impairment and dementia among individuals of differing cultural, ethnic, and socioeconomic backgrounds, improve early detection; and sharpen the accuracy of the differential diagnosis of dementia. Subjects are recruited from the Columbia University memory centers operating at The Neurological Institute, New York State Psychiatric Institute, Harlem Hospital Satellite, and from volunteers and community-dwelling persons receiving healthcare from a nearby collaborating facility, Isabella Geriatric Center. The Clinical Core recruits a sample including about 20% Hispanics, 11% African-Americans, and 2.5% Asians. The Core performs rigorous standardized medical, neurologic, psychiatric, neuropsychological, neuroimaging, and biological sample evaluation. The Core interacts closely with the Genetics Core in genotyping, storage, and disbursement of samples. The Core works integrally with the Data Core to ensure standardized, high quality, complete data collection including the Uniform Data Set (UDS). Interface with Education Core improves visibility and understanding of diseases, clinical trials, and autopsy program. Coordination with Neuropathology Core results in maximizing utility of brain tissue for genetic, mitochondrial, epigenetic, biochemical, proteomic, and gene expression investigations. Subjects enroll in affiliated federal, foundation, and pharmaceutical company funded research studies. These include clinical drug trial, genetic epidemiology, neuroimaging and neuropsychological studies, and research into risk factors, predictors, and contributing conditions in cognitive change during aging and dementia.